Huanjing Kexue/Environmental Science最新文献

{"title":"[Role of Ammonia in Aerosol Liquid Water, pH, and Secondary Inorganic Aerosols Formation at an Ammonia-rich City in Changzhou].","authors":"Yi-Jun Yu, Min Zhuang, Zhen Wang, Kai-Ji Li, Wei-Fen Yang","doi":"10.13227/j.hjkx.202309100","DOIUrl":"https://doi.org/10.13227/j.hjkx.202309100","url":null,"abstract":"<p><p>Ammonia （NH₃） is an important alkaline reactive nitrogen, which, as a precursor of fine particulate matter, raises public health issues. In this study, online NH₃, SO₂, NO₂, PM_2.5, and its water-soluble inorganic ions were detected to deduce the influence of NH₃ on aerosol liquid water content （AWC） and aerosol pH, including the formation of water-soluble secondary ions in PM_2.5 in winter in Changzhou, an ammonia-rich city in the Yangtze River Delta area in winter. The results showed that NH₄⁺ mainly existed in the form of NH₄NO₃ and （NH₄）₂SO₄, and the remaining NH₄⁺ existed as NH₄Cl. Owing to the NH₃-NH₄⁺ buffer system, the aerosol pH values were found at 4.2 ± 0.4, which was positively correlated with the NH₃ content. The aerosol pH value variation narrowed with the increase in PM_2.5 concentration and tended to be between 4 to 5. AWC increased exponentially with the increase in humidity and SNA content, among which NH₄NO₃, （NH₄）₂SO₄, and NH₄Cl contributed 58.5%, 18.4%, and 8.3%, respectively, due to their hygroscopicity. Aerosol pH, AWC, and NH₃-NH₄⁺ conversion promoted the gas-to-particle conversion of SO₂ and NO₂. In Changzhou, rich NH₃-NH₄⁺ were found to maintain relatively high pH values, push up AWC, and promote the heterogeneous reaction of SO₂, whereas NO₃^- generation was dominated by a homogeneous reaction, which was accelerated by NH₃. According to the simulation results, relatively noticeable changes in aerosol pH and AWC could be found by the reduction of up to 30% of NH₃.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142018939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effects of Long-term Biochar Addition on Denitrification N₂O Emissions from Bacteria and Fungi in Paddy Soil].","authors":"Meng-Jie Wang, Wen-Ting Jiang, You-Xiang Xu, Yu-Xue Liu, Hao-Hao Lü, Yu-Ying Wang, Sheng-Mao Yang, Li-Li He, Yan-Jiang Cai","doi":"10.13227/j.hjkx.202309176","DOIUrl":"https://doi.org/10.13227/j.hjkx.202309176","url":null,"abstract":"<p><p>Denitrification driven by bacteria and fungi is the main source of nitrous oxide （N₂O） emissions from paddy soil. It is generally believed that biochar reduces N₂O emissions by influencing the bacterial denitrification process, but the relevant mechanism of its impact on fungal denitrification is still unclear. In this study, the long-term straw carbonization returning experimental field in Changshu Agricultural Ecological Experimental Base of the Chinese Academy of Sciences was taken as the object. Through indoor anaerobic culture and molecular biology technology, the relative contributions of bacteria and fungi to denitrifying N₂O production in paddy soil and the related microorganism mechanism were studied under different long-term biochar application amounts （blank, 2.25 t·hm^-2, and 22.5 t·hm^-2, respectively, expressed by BC0, BC1, and BC10）. The results showed that compared with that in BC0, biochar treatment significantly reduced N₂O emission rate, denitrification potential, and cumulative N₂O emissions, and the contribution of bacterial denitrification was greater than that of fungal denitrification in all three treatments. Among them, the relative contribution rate of bacterial denitrification in BC10 （62.9%） was significantly increased compared to BC0 （50.8%）, whereas the relative contribution rate of fungal denitrification in BC10 （37.1%） was significantly lower than that in BC0 （49.2%）. The application of biochar significantly increased the abundance of bacterial denitrification functional genes （<i>nirK</i>, <i>nirS</i>, and <i>nosZ</i>） but reduced the abundance of fungal <i>nirK</i> genes. The contribution rate of fungal denitrification was significantly positively correlated with the N₂O emission rate and negatively correlated with soil pH, TN, SOM, and DOC. Biochar may have inhibited the growth of denitrifying fungi by increasing pH and carbon and nitrogen content, reducing the abundance of related functional genes, thereby weakening the reduction ability of NO to N₂O during fungal denitrification process. This significantly reduces the contribution rate of N₂O production during the fungal denitrification process and the denitrification N₂O emissions from paddy soil. This study helps to broaden our understanding of the denitrification process in paddy soil and provides a theoretical basis for further regulating fungal denitrification N₂O emissions.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142018962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Soil Cadmium Prediction and Health Risk Assessment of an Oasis on the Eastern Edge of the Tarim Basin Based on Feature Optimization and Machine Learning].","authors":"Jing-Yu Liu, Ruo-Yi Li, Yong-Chun Liang, Lei Liu, Fang Yin, Su Tang, Lin-Sen He, Yi Zhang","doi":"10.13227/j.hjkx.202308010","DOIUrl":"https://doi.org/10.13227/j.hjkx.202308010","url":null,"abstract":"<p><p>Soil heavy metal pollution poses a serious threat to food security, human health, and soil ecosystems. Based on 644 soil samples collected from a typical oasis located at the eastern margin of the Tarim Basin, a series of models, namely, multiple linear regression （LR）, neural network （BP）, random forest （RF）, support vector machine （SVM）, and radial basis function （RBF）, were built to predict the soil heavy metal content. The optimal prediction result was obtained and utilized to analyze the spatial distribution features of heavy metal contamination and relevant health risks. The outcomes demonstrated that： ① The average Cd content in the study area was 0.14 mg·kg^-1, which was 1.17 times the soil background value of Xinjiang, making it the primary factor of soil heavy metal contamination in the area. Additionally, the carcinogenicity risk coefficients of Cd for both adults and children were less than 10^-4, indicating that there were no significant long-term health risks for humans in the area. ② The estimation accuracies of the five inversion models were compared, and the validation set of the RF model had an <i>R</i>² value of 0.763 7, which was the highest among the five models. Additionally, the RMSE, MAE, and MBE of the RF model were the smallest among the five models. Therefore, the predicted values of the RF model were most consistent with the measured values of the soil Cd content. The predicted map of soil Cd distribution derived from the RF model coincided best with the interpolation map. ③ The RF model outperformed the other four models in predicting health risks associated with the soil Cd element for both adults and children, resulting in better prediction results. Comparatively, the predicted values of the LR model in the validation set varied greatly, leading to unreliable results. It was demonstrated that the RF was the best model for predicting soil Cd content and evaluating health risks in the study area, considering its superior generalization capability and anti-overfitting ability.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142018943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Pollution Characteristics and Source Apportionment of VOCs in Urban Areas of Shijiazhuang in Spring].","authors":"Yu-Jie Yu, Chen-Qiang Yang, Rui Yang, Shun-Xin Zhang, He-Yu Wang, Da-Xi Liu, Sai-Sai Nie, Shuai Wang, Jian-Sheng Cui, Shuang-Jiang Li, Yun-Xia Wang","doi":"10.13227/j.hjkx.202307088","DOIUrl":"https://doi.org/10.13227/j.hjkx.202307088","url":null,"abstract":"<p><p>Samples of ambient volatile organic compounds （VOCs） were collected using SUMMA canisters at three Country Control Sites in Shijiazhuang during the spring of 2019, 2021, and 2022, which were detected using gas chromatography/mass spectrometry （GC/MS）. To investigate the characteristics and temporal variations of VOCs mass concentration levels, the online monitoring data of ozone （O₃） and PM_2.5 at the same site were also collected. Subsequently, the ozone formation potential （OFP） and secondary organic aerosol formation potential （SOAFP） were utilized to assess the chemical activity of VOCs. Additionally, the potential source areas of VOCs in spring in Shijiazhuang were further identified using the potential source contribution factor （PSCF） method and concentration weight trajectory analysis （CWT）. Hence, the major VOCs sources were evaluated with the VOCs initial mixing ratio. The results demonstrated that the averaged concentration of VOCs during the polluted period and clean period of spring in Shijiazhuang were 191.17 μg·m^-3 and 122.18 μg·m^-3, respectively. Meanwhile, the OFP was 361.23 μg·m^-3 during the polluted period and 266.96 μg·m^-3 during the clean period, whereas the SOAFP was 1.98 μg·m^-3 and 1.61 μg·m^-3, respectively. Therefore, effective control of benzene, toluene, ethylbenzene, and xylene （BTEX） is crucial for reducing PM_2.5 and O₃ pollution. Based on the results obtained from weight PSCF and CWT, the potential source areas of VOCs were further identified to be primarily located in the eastern Yuhua District, the high-tech district, and the northern Luancheng District of Shijiazhuang. These areas were influenced not only by local emissions but also by transport from neighboring regions, in which consistency between the CWT and PSCF results further supported these findings. Furthermore, the results obtained from the benzene/toluene/ethylbenzene （B/T/E） and xylene/benzene （X/B） ratios indicated that the main sources of VOCs in Shijiazhuang in spring were vehicle exhaust sources and burning sources, leading to a more serious air mass aging phenomenon. Hence, controlling vehicle emissions and implementing regional cooperative measures are the effective strategies for optimizing the air quality of Shijiazhuang.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142018992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Advances in Research of the Effects and Mechanisms of Polyethylene Microplastics on Soil Nitrogen Transformation].","authors":"Shu-Tao Wang, Wan-Qing Wang, Sa-Shuang Rong, Yu-Xin Li, Xin-Xin Wang, Pan Liang, Wei Liu","doi":"10.13227/j.hjkx.202308166","DOIUrl":"https://doi.org/10.13227/j.hjkx.202308166","url":null,"abstract":"<p><p>In the agricultural lands of China, polyethylene is the main component of microplastics （MPs）, with characteristics such as small size, wide distribution, easy accumulation, and difficult degradation. Therefore, it may have an impact on the elemental cycling process of the soil. On the basis of reviewing the key literatures in the past few years, this study systematically analyzed and summarized the key factors and processes of the polyethylene microplastics （PE-MPs） affecting soil nitrogen transformation. On the one hand, PE-MPs directly affected the activities of microorganisms and key enzymes related to soil nitrogen transformation by enriching microorganisms, selecting colonized microbial populations, and releasing additives. On the other hand, PE-MPs had indirect impacts on the activities of microorganisms and key enzymes related to soil nitrogen transformation by affecting soil physicochemical properties of soil and changing the microenvironment for microbial growth. Moreover, phthalates, an important additive of the MPs, may be the key factor affecting soil nitrogen transformation in the short-term. Finally, we posed key scientific issues that should be further studied in order to provide scientific support for nitrogen nutrition regulation and ecological risk assessment of soils contaminated by PE-MPs.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142018924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Source Apportionment and Response to Landscape Pattern of Health Risk of Cultivated Soil Heavy Metals].","authors":"Guang-Jing Bao, Chao Ji, Da-Wei Hou, Fa-Zhi Li, Ai-Ping Deng","doi":"10.13227/j.hjkx.202309003","DOIUrl":"https://doi.org/10.13227/j.hjkx.202309003","url":null,"abstract":"<p><p>Heavy metal pollution mainly caused by human activities is becoming increasingly prominent and threatening human health and ecosystem safety in soil, which is a non-renewable natural resource that humans rely on for survival and development. Assessment and analysis of soil heavy metal health risk is significant for protecting human health, preventing soil pollution, and maintaining ecosystem security. Based on the investigation of heavy metals, including Cr, Pb, Cd, As, and Hg, in cultivated soil in Liuhe District, the health risk assessment model was used to identify the health risk characteristics of heavy metals, and the spatial distribution, main sources, and responses to landscape patterns were explored by using inverse distance weight interpolation, positive definite matrix factorization, landscape pattern index, and redundancy analysis. The results showed that the coefficients of variation corresponding to Cr, Pb, Cd, As, and Hg in the study area were 0.19, 0.36, 0.23, 0.52, and 1.16, respectively, all of which belonged to moderate or high variability, indicating that they had high spatial heterogeneity and were susceptible to human factors. Cr, Pb, and As were the main health risk characteristic factors in the study area, with the carcinogenic risks to children ranging from 13.307×10^-6 to 38.400×10^-6, 0.839×10^-6 to 3.250×10^-6, and 4.548×10^-6 to 16.680×10^-6, respectively, which were higher than those in adults. Agricultural production activities, industrial production, and transportation activities were the main sources of heavy metals, with carcinogenic risks to children of 17.946×10^-6 and 12.941×10^-6, respectively. Furthermore, high-risk areas caused by agricultural production activities were mainly concentrated in the northern area of Liuhe District and showed an increasing trend from south to north and from the center to the periphery. The surrounding areas caused by industrial production activities and transportation were mainly concentrated in the chemical industry park and economic development zone of Liuhe District and showed a spatial agglomeration feature of decreasing from south to north and from the core to the periphery. The cumulative explanatory value of the landscape pattern index for the comprehensive carcinogenic risk to children was 0.463, and patch density, patch proportion in landscape area, patch aggregation degree, and maximum patch index had significant effects on the comprehensive carcinogenic risk in children, and the corresponding explanatory values were 0.422, 0.274, 0.351, and 0.232, respectively. This study had important theoretical and practical significance for expanding the perspective of environmental health research, promoting the transformation of soil heavy metal management methods and safeguarding regional population health.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142018944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Interaction Effects of Vegetation and Soil Factors on Microbial Communities in Alpine Steppe Under Degradation].","authors":"Huan Xu, Ming-Jun Ding, Hua Zhang, Yue-Ju Zhang, Peng Huang, Yu-Ping Wu, Tian-E Zou, Neng-Yu Wang, Huan Zeng","doi":"10.13227/j.hjkx.202307217","DOIUrl":"https://doi.org/10.13227/j.hjkx.202307217","url":null,"abstract":"<p><p>To clarify the regulating effect of vegetation and soil factors on microbial communities in the alpine steppe under degradation on the Qinghai-Xizang Plateau, the alpine steppe in the Sanjiangyuan area of the Qinghai-Tibet Plateau was chosen. We analyzed the differences in vegetation and soil factors in different stages of degradation （non-degradation, moderate degradation, and severe degradation） and detected the variations in microbial community characteristics in the alpine steppe under different degradation stages using high-throughput sequencing technology. Eventually, redundancy analysis （RDA） and multiple regression matrixes （MRM） based on the similarity or dissimilarity matrix were used to identify key environmental factors regulating microbial （bacterial and fungal） community changes under degradation. The results showed that the degradation of the alpine steppe significantly changed the community coverage, height, biomass, and important value of graminae； significantly reduced the contents of soil organic matter, total nitrogen, total phosphorus, and silt； and increased the soil bulk density and sand content. Degradation did not change the composition of bacteria and fungi, but their composition proportions changed and also resulted in the loss of microbial richness （Chao1 index and Richness index） but did not significantly change the microbial diversity （Shannon index）. With the occurrence of degradation, the vegetation characteristics, soil physicochemical properties, and microbial diversity showed a consistent change trend. Combined with the characteristics of the network topology changes （the number of nodes and clustering coefficient significantly decreased）, it was found that degradation of the alpine steppe led to the decline of interspecies interactions, decentralization of network, and homogenization of microorganisms, but the cooperation relations among the species were maintained （positive correlation connections accounted for more than 90% in all degradation stages）. Under the alpine steppe degradation, the vegetation-soil interaction had the greatest effect on soil bacterial community, whereas soil physicochemical properties had the greatest influence on soil fungal community. Specifically, vegetation community height, biomass, and soil bulk density were the mutual factors regulating soil microorganisms, whereas the vegetation Simpson index, important value of graminae, soil total phosphorus, total potassium, and silt content were the unique factors affecting the soil bacterial community, and soil pH and total nitrogen content were the particular factors affecting the soil fungal community.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141634778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Immobilization of Heavy Metals by Phosphorus-solubilizing Bacteria and Inhibition of Cd and Pb Uptake by Wheat].","authors":"Nan-Nan Su, Qing-Zhao Zhao, Fang Wang, Tian-Ci An, Jing-Jing Niu, Jia-Xin Yan, Jian-Jun Yang, Hui Han","doi":"10.13227/j.hjkx.202308206","DOIUrl":"https://doi.org/10.13227/j.hjkx.202308206","url":null,"abstract":"<p><p>Phosphorus-solubilizing microorganisms convert insoluble phosphorus in the soil into phosphorus that can be absorbed by plants. Soluble phosphate combines with heavy metals to form precipitation, reducing the content of available heavy metals, thereby reducing the absorption of heavy metals by crops, which plays an important role in the remediation of heavy metal-contaminated soil. The effects of the immobilization of Cd and Pb and the release of PO₄^3- by the phosphorus-solubilizing bacterium <i>Klebsiella</i> sp. M2 were studied through solution culture experiments. In addition, the effects of strain M2 on wheat uptake of Cd and Pb and its microbiological mechanism were also explored through pot experiments. The results showed that strain M2 reduced the concentrations of Cd and Pb and increased the concentration of PO₄^3- in the solution through cell wall adsorption and induced phosphate precipitation. Pot experiments showed that compared to those in the CK group and inactivated strain M2 group, inoculation with live strain M2 significantly increased （123%-293%） the contents of Ca₂-P and Ca₈-P in rhizosphere soil, decreased the content of DTPA-Cd （34.48%） and DTPA-Pb （36.72%） in wheat rhizosphere soil, and thus hindered the accumulation of Cd and Pb in wheat grains. Moreover, high-throughput sequencing results showed that strain M2 significantly increased the diversity of wheat rhizosphere bacterial communities； increased the relative abundance of Proteobacteria, Gemmatimonadetes, and Bacteroidota in wheat rhizosphere soil； and increased the proportion of heavy metal-immobilizing and phosphorus-promoting bacteria in wheat rhizosphere soil （mainly <i>Sphingomonas</i>, <i>Nocardioides</i>, <i>Bacillus</i>, <i>Gemmatimonas</i>, and <i>Enterobacter</i>）. These bacterial genera played an important role in immobilizing heavy metals and preventing wheat from absorbing heavy metals. These results provide bacterial resources and theoretical basis for the bioremediation of heavy metal-contaminated farmland.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141634777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effects of Different Microbial Fertilizers on Soil Quality and Maize Yield in Coastal Saline Soil].","authors":"Jing Ye, Ying Chen, Shuang Qu, Wen-Chao Zhao","doi":"10.13227/j.hjkx.202307148","DOIUrl":"https://doi.org/10.13227/j.hjkx.202307148","url":null,"abstract":"<p><p>Microbial fertilizers have the characteristics of high efficiency and environmental protection in improving saline soils, and the application of functional microbial fertilizers is of great significance for the green abatement of saline barriers and the improvement of soil quality in coastal areas. The experiment was based on moderately saline soil in the coastal area of Hebei Province, with corn as the indicator crop, on the basis of conventional chemical fertilizer application. Different microbial fertilizer treatments, namely, T1 （conventional chemical fertilizer 750 kg·hm^-2 + compound microbial agent 75 kg·hm^-2）, T2 （conventional chemical fertilizer 750 kg·hm^-2 + <i>Bacillus megaterium</i> 300 kg·hm^-2）, T3 （conventional chemical fertilizer 750 kg·hm^-2 + <i>B. mucilaginosus</i> 300 kg·hm^-2）, T4 （conventional chemical fertilizer 750 kg·hm^-2 + organic silicon fertilizer 600 kg·hm^-2）, T5 （conventional chemical fertilizer 750 kg·hm^-2 + bio-organic fertilizer 600 kg·hm^-2）, T6 （conventional fertilizer 750 kg·hm^-2 + active microalgae 15 kg·hm^-2）, and CK （only fertilizer 750 kg·hm^-2）, were used for these seven treatments, to study the effects of different microbial fertilizers on soil nutrients, salinity, bacterial community, and corn yield and economic efficiency during two critical periods （V12 stage and maturity stage） of corn. The results showed that compared with that in CK, T1 significantly increased soil total nitrogen （TN） and available phosphorus （AP） contents during the whole growth period. Over the whole reproductive period, soil organic matter （OM） at maturity increased by 10.35% over the V12 stage compared to that in CK, but there was no significant difference between treatments. Compared with that in CK, T5 and T6 significantly reduced soil total salinity and Ca²⁺ content during the whole growth period by an average of 14.51%-18.48% and 24.25%-25.51%. T1 significantly increased the bacterial diversity index over the whole growth period by 45.16% compared to that in CK. The dominant soil phyla were Actinobacteria, Proteobacteria, Acidobacteria, and Chloroflexi, and the dominant genera were <i>Bacillus</i> and <i>Geminicoccaceae</i>. The most abundant functions of the bacterial community in the study area were chemoheterotrophy and aerobic chemoheterotrophy, with average relative abundances of 28.89% and 27.11%, and T3 and T6 significantly improved soil N cycling function. The results of redundancy analysis （RDA） indicated that Na⁺, SO₄^2-, pH, and EC were important factors driving the structure of the bacterial community, and correlation heatmaps showed that Na⁺, SO₄^2-, pH, and EC were significantly and positively correlated mainly with the phylum Planctomycetota, whereas soil OM and TN were significantly and positive","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141634800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Evolution of Physical and Chemical Characteristics of Atmospheric Precipitation and Its Significant Impacts on the Environment in Beijing].","authors":"Li-Hui Han, Qian Xiao, Xue-Mei Yang, Chao-Nan Qi, Jian Tian, Tong Lan, Shui-Yuan Cheng, Ai-Hua Zheng, Jing-Hua Guo","doi":"10.13227/j.hjkx.202307273","DOIUrl":"https://doi.org/10.13227/j.hjkx.202307273","url":null,"abstract":"<p><p>Atmospheric precipitation samples were collected in 2018, 2019, and 2021 in Beijing to study the concentrations and changes of the main metal elements and water-soluble ions； the wet deposition fluxes of heavy metals, water-soluble ions, dissolved inorganic nitrogen, and sulfur in the atmospheric precipitation and their impacts on the ecological environment； and the scavenging mechanisms of the typical precipitation to atmospheric pollutants during the study period. The results showed that the precipitation in Beijing during the study period was mostly neutral or alkaline, and the frequency of acid rain occurrence was very low, only accounting for 3.06%. The total concentrations of major metal elements in 2018, 2019, and 2021 were （4 787.46 ±4 704.31）, （7 663.07 ±8 395.05）, and （2 629.13 ±2 369.51） μg·L^-1, respectively. The total equivalent concentrations of ions in 2018, 2019, and 2021 were （851.68 ±649.16）, （973.98 ±850.94）, and （644.31 ±531.16） μeq·L^-1, respectively. The interannual changes in major metal elements and ions followed the order of 2019 &gt; 2018 &gt; 2021. The seasonal average total concentrations of major metal elements in spring, summer, autumn, and winter were （9 624.25 ±7 327.92）, （4 088.67 ±5 710.14）, （3 357.68 ±3 995.64）, and （6 203.19 ±3 857.43） μg·L^-1, respectively, and the seasonal average total equivalent concentrations of ions in spring, summer, autumn, and winter were （1 014.71 ±512.21）, （729.83 ±589.90）, （724.35 ±681.40）, and （1 014.03 ±359.67） μeq·L^-1, respectively, all presenting the order of spring &gt; winter &gt; summer &gt; autumn. NO₃^- and SO₄^2- were the main acid-causing ions in precipitation, whereas NH₄⁺ and Ca²⁺ were the main acid-neutralizing ions. The wet deposition fluxes of the heavy metal Cd were very low [（0.05 ±0.01） mg·（m²·a）^-1], only accounting for （0.13 ±0.04）% of the total wet deposition fluxes of main metal elements； however, its soil safety years were 291 years, significantly lower than those of other heavy metals, displaying that its ecological risk was relatively the highest. The total wet precipitation flux of water-soluble ions NH₄⁺, Ca²⁺, NO₃^-, and SO₄^2- accounted for （85.72 ±2.18）% of the wet precipitation flux of total ions, suggesting that their comprehensive impact on the ecological environment might have been higher. DIN wet deposition flux was mainly characterized by NH₄⁺-N, which had a positive impact on the ecological environment in summer. SO₄^2--S wet deposition flux was higher in summer, so its positive impact on the ecological environment was also greater. The scavenging effects of atmospheric precipitations to pollutants from the air were impacted by various factors, and the synergism effects of these factors co","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141634773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}